Screw jack



March 10, 1931'. E. L, WILSON 1,795,630

SCREW JACK Filed April 24, 1928 w 5/ v lnventor & F I By %W A llorncyPatented Mar. 10, 1931 UNITED STATES PATENT O F EARL L. WILSON, OFSPOKANE, WASHINGTON, AS SIGNOR OF'ONE-FOURTH TO RANMOND 1 E. RAMSEY, O1SPOKANE, WASHINGTON, AND ONE-HALF TO LILLIAN D. LANG, 'OF

KELLOGG, IDAHO.

SCREW JACK V Application filed April 24,

My present invention relates to an improved screw jack of the typeusually employed in connection with the lifting of automobiles, but itwill be understood, of course, that the ack of my invention may beutilized for many different purposes and in various ways. In carryingout my invention I utilize a series of telescopic screw threadedsections that may be compactly arranged in the hollow base or housing ofthe jack when the jack is not in use, or when only a small space isavailable in which the jack is to be used. The telescopic screw threadedsections may be successively turned for the purpose of extending theheight of the jack, and means are provided for operating the screw jackas will be described.

The invention consists in certain novel combinations and arrangements ofparts as will hereinafter be more fully set forth and claimed.

In the accompanying drawings I have illustrated one complete example ofthe physical embodiment of my invention wherein the parts are combinedand arranged according to the best mode I have so far devised for thepractical application of the principles of my invention.

Figure 1 is a vertical sectional view of the jack in extended position.Figure 2 is a transverse sectional view of a base plate for use With thejack as at line 2, 2, of Figure 4:. Figure 3 is a top plan view of apart of the operating lever as at line 5, 5, of Figure 1. Figure 4 is atop plan view of the base plate as at line 4, 4. Figure 5 is an enlargeddetail bottom plan view partly in section showing the ratchet mechanism.Figure 6 is a perspective view showing the end of the operating lever asat line 6, 6, of Figure 5.

In the preferred form of my invention as illustrated in the drawings, Iuse a hollow base or cylindrical housing 1, and an intermediate section2, which is threaded into the housing 1 and fashioned with both externaland internal threads, and a third section 8, which is provided withexternal threads, on gaged with the intermediate section. The hollowbase or housing 1 is fashioned with an external annular flange 4, theintermedi- 1928. Serial No. 272,401.

ate section has an external annular retaining flange 5 within the hollowbase, and the screw section 3 has a retaining annular external flange 6within the intermediate section 2 as indicated in Figure 1. A screw bar7. is threaded in the upper end of the top section 3 and provided with aretaining head 7f. Itwill be apparent that the screw bar and the screwsections 3 and 2 may be compactly stored within the hollow base orhousing 1 when these partsare properly turned to screwthem home.

A base plate 8 in the form of a circular disk is provided for use withthe housing 1 and the housing 1 and the base plate, the housing isprovided with a number of lugs 11 on its lower edge and these lugs areadapted to fit into sockets 12 in theupper face of'the base plate, lVhenthe base plate is not used these lugs 11 on the housing provideanchoring means for the housing or base of the jack.

The several sections of the jack may be screwed one within the other byoperation of the lever 13 that is arranged in horizontal posltion andprovided at one end with a spring pressed pin 14 projecting therefrom.The lever is preferably angular in cross section and is detachablyfitted into a socket 15 of the ratchet arm 16. The lever is adjustableso that the pin 14 may be fitted into either of the openings 14: or 15in the base of the socket 15'. The operating lever is fashioned with asectional head to fit about the upper end of the screw bar 7 and thishead includes flanges 17 on the ratchet arm, semi-circular section 18having flanges 19 and the bolts 19' in the flanges 17 and 19 for formingthe parts into a rigid, open head that fits loosely around the upper endof the screw 7.

The ratchet arm carries a double ratchet 20 which is pivoted in the armat 21 and this ratchet has opposed pawls 22 and 23 that are adapted foralternate use to co-act with the teeth of the ratchet wheel 24. Theratchet wheel 24 is secured to the screw 7 and rotates with the screwwhen'the latter is actuated by the oscillating movement of the operatinglever for raising or lowering the ack.

It will be apparent that one pawl 22 coacts with the ratchet wheel 24for lowering the jack, while the pawl 23 may be used with the ratchet 24for raising the jack. lVhen the movement of the jack is to be reversed,the lever 13 with its pin 14 is withdrawn from the socket 15, theratchet 20 is turned on its pivot, and then the lever is turned throughan angle of degrees on its longitudinal aXis and inserted in the socketso that the pin 14 will co-act with the ratchet 20 at a side opposite tothe side previously engaged.

On the upper end of the screw bar a bearing head 25 is loosely arranged,and preferably ball bearings 26 are interposed between this bearing headand the ratchet head of the ratchet arm.

From the above description taken in connection with my drawings it willbe apparent that I have provided a powerful, strong, and sturdy screwjack which may be manipulated with facility and which is capable oflifting heavy loads with expenditure of a minimum ofpower.

Having thus fully described my invention what I claim as new and desireto secure by Letters Patent is The combination with a telescopicextensible jack having a lower annular flange and anchoring lugs on itsbase, of a base plate having spring clips projecting above its lateraledge for engaging said flange and sockets in its upper face forco-acting wit-h said lugs.

In testimony whereof I affix my signature.

EARL L. WIIIsoN.

